CN102234774A

CN102234774A - System and methods for high-rate co-sputtering of thin film layers on photovoltaic module substrates

Info

Publication number: CN102234774A
Application number: CN2011101162781A
Authority: CN
Inventors: J·A·德雷顿; R·D·戈斯曼
Original assignee: Primestar Solar Inc
Current assignee: Primestar Solar Inc
Priority date: 2010-04-29
Filing date: 2011-04-29
Publication date: 2011-11-09
Also published as: EP2385151A1; AU2011201788A1; US20110266141A1

Abstract

Systems and methods for deposition of a thin film layer on photovoltaic (PV) module substrates (12) are generally provided. The system can include a sputtering chamber (166) configured to receive the substrates (12), at least two targets (201, 202) positioned within the sputtering chamber (166), and an independent power source (168) connected to each target (201, 202). Each target (201, 202) can be positioned within the sputtering chamber (166) to face the substrates (12) such that the targets (201, 202) are simultaneously sputtered to supply source material to a plasma field (174) for forming a thin film layer on a surface of the substrates (12). The multiple targets (201, 202) can also be positioned such that a facing axis (211, 212) extending perpendicularly from a center of each target (201, 202) converges at a point (205) on the surface of the substrate (12).

Description

The system and method that is used for the high speed cosputtering of photovoltaic module film on substrate layer

Technical field

Theme relate generally to disclosed herein is used for the system and method for the depositing of thin film on the substrate, and more particularly, relates to being used for from a plurality of target cosputterings to form the high throughput systems of thin film layer at the photovoltaic module substrate.

Background technology

Film photovoltaic (PV) module (being also referred to as " solar panel " or " solar energy module "), especially based on the module as the photoresponse device of Cadmium Sulfide (CdS) paired cadmium telluride (CdTe), winning in the industry and accepting widely and interest.CdTe has the semiconductor material that is particularly suitable for sun power (sunlight) is converted to the characteristic of electric power.For example, CdTe has the band gap of 1.45eV, and this makes and compare with the semiconductor material than low band-gap (1.1eV) that is used in history in the solar cell application that it can change more energy from solar spectrum.And, compare with material than low band-gap, CdTe switching energy more effectively under lower or diffuse light conditions, and thereby with during other conventional material is compared by day or have longer effective switching time under low light (for example cloudy) condition.

Typically, CdTe PV module is included in a plurality of thin film layers that are deposited on before the deposition of CdTe layer on the glass substrate.For example, transparent conductive oxide (TCO) layer at first is deposited on the surface of glass substrate, and resistive transparent caching thing (RTB) layer is coated on the tco layer then.The RTB layer can be zinc tin oxide (ZTO) layer and can be called " ZTO layer ".Cadmium Sulfide (CdS) layer is coated on the RTB layer.These different layers can be with the sputter deposition craft coating of routine, and this technology comprises from target (that is, material source) blasting materials, and the material that sprays is deposited on the substrate to form film.

Use the solar energy system of CdTe PV module to be considered to usually aspect every watt of cost of the power that is produced to be commerce the most cost-effective in can the acquisition system.Yet although CdTe has multiple advantage, sun power is as additional source or the sustainable business development of main source and the ability that efficient PV module is depended on a large scale and produces in the mode of cost economy in approval of industry or civilian electric power.The cost of capital relevant with the production of PV module particularly for the deposition of a plurality of thin film layers discussed above required machinery and time, is that main commerce is considered.

Therefore, have the demand that continues for the system that improves in the industry, this system is used for the PV module particularly based on the viable economically and effective scale operation of the module of CdTe.

Summary of the invention

The partly statement in the following description of many aspects of the present invention and advantage perhaps can become obviously from this description, perhaps can learn by practice of the present invention.

Many-sided embodiment according to the present invention comprises and is used for thin film layer is deposited on system on photovoltaic (PV) module substrate.This system can comprise the sputtering chamber that is configured to admit substrate, is positioned at least two targets in this sputtering chamber, and is connected to the independently power supply on each target.Each target can become towards substrate in this sputter indoor positioning, makes target by the while sputter, thereby source material is supplied to the plasma field that is used for forming thin film layer on the surface of substrate.These a plurality of targets also can be located such that from the axis in opposite directions of the central vertical extension of each target and assemble at the lip-deep point of substrate.

Also provide generally and be used for a plurality of thin film layers are deposited on method on photovoltaic (PV) module substrate.In one embodiment, this method can comprise with the substrate transfer on the carriage by sputtering chamber and when substrate moves through sputtering chamber at least two targets of sputter on substrate, to form thin film layer.These at least two targets can become towards substrate in this sputter indoor positioning, make target by the while sputter, thereby source material is supplied to the plasma field that is used for forming thin film layer on the surface of substrate.Each target can be located such that from the axis in opposite directions of the central vertical extension of each target and assemble at the lip-deep point of substrate.

The method of making the Cadimium telluride thin film photovoltaic devices also is provided generally.This method can comprise simultaneously and from first target (for example, comprising Cadmium oxide) and second target (for example, comprising stannic oxide) including transparent conducting oxide layer being splashed on the substrate.First target and second target can be located such that from the axis in opposite directions of the central vertical extension of each target and assemble at the lip-deep point of substrate.Axis in opposite directions can form with y axis perpendicular to the surface of substrate about 30 ° to about 60 ° angle.On the transparent oxide layer, can deposit resistive transparent caching thing layer.On resistive transparent caching thing layer, can deposit cadmium sulfide layer.On cadmium sulfide layer, can deposit cadmium-telluride layer.

With reference to following description and appended claims, these and other feature of the present invention, aspect and advantage will become better understood.In conjunction with in this manual and the accompanying drawing that constitutes the part of this specification sheets illustrate embodiments of the invention, and with describe one and be used from and explain principle of the present invention.

Description of drawings

Stated complete and disclosing of can implementing of the present invention at those skilled in the art in this manual, comprised its optimal mode, it is with reference to accompanying drawing, wherein:

Fig. 1 is the viewgraph of cross-section of CdT photovoltaic module;

Fig. 2 has shown the top plan according to an example system of many aspects of the present invention;

Fig. 3 has shown the top plan according to an alternative system of many aspects of the present invention;

Fig. 4 is the skeleton view of an embodiment of substrate holder structure;

Fig. 5 is the skeleton view of an alternative of substrate holder structure;

Fig. 6 is the sketch of an embodiment that is used for the sputtering chamber of the depositing of thin film on the substrate;

Fig. 7 is the sketch of an alternative of sputtering chamber; And

Fig. 8 has shown from the vertical view of an exemplary embodiment of two target cosputterings.

The repeated use of reference number is intended to represent identical or similar feature or element in this specification sheets and the figure.

The component tabulation

Angle θ ₁

Angle θ ₂

CdTe module 10

Substrate 12

Transparent conductive oxide (TCO) layer 14

Resistive transparent caching thing (RTB) layer 16

Cadmium sulfide layer 18

Cadmium-telluride layer 20

Back contact layer 22

System 100

First process side 102

Arrow 103

Processing stand 104

Entrance 106

Exit point 108

Second process side 110

Direction arrow 111

Processing stand 112

Inlet 114

Exit point 116

First transition point 118

Second transition point 120

Automatic rotating disk 121

Carriage 122

Framing member 124

Module 125

Handling machinery 126

Vertical deposition module 128

Vacuum load module 132

Load buffer module 134

Processing buffer module 136

Post-treatment buffer module 138

Outlet buffer module 140

Outlet module 142

External buffer 144

Cooling point 148

Unloading point 150

Load(ing) point 152

Vacuum locking valve 154

Motor 156

Controller 158

Centring system controller 160

Vacuum pump 162

Vacuum pump 164

Turbomolecular pump 165

Sputtering chamber 166

Power source 168

Negative electrode 170

Anode 172

Target source material 176

Plasma field 174

First target 201

Second target 202

X-axis line 203

Y-axis line 204

Central point 205

Axis 211 in opposite directions

Axis 212 in opposite directions

Embodiment

Now will be in detail with reference to embodiments of the invention, illustrate its one or more examples in the drawings.Each example provides as explanation of the present invention rather than restriction of the present invention.In fact, will be apparent that in the present invention those skilled in the art and can make multiple remodeling and modification, and not deviate from scope of the present invention or spirit.For example, can use and produce another embodiment with another embodiment as the part of embodiment diagram or the feature described.Therefore, its intention is that the present invention covers interior this type of remodeling and the modification of scope of appended claims and Equivalent thereof.

In the present invention is open, when layer be described as be in another layer or substrate " on " or when " top ", should understand that layer can be in direct contact with one another, another layer or feature are perhaps arranged between layer.Therefore, these terms only are to describe layer for the relative position of each other, and not necessarily mean " atop " because up or the relative position of below depend on the orientation of this device for the beholder.In addition, although the invention is not restricted to any specific film thickness, the term of describing any rete of photovoltaic devices " approaches " and is often referred to rete and has thickness less than about 10 microns (" micron " or " μ m ").

Will be understood that all scopes (that is subrange) that the scope that this paper mentions and the limit comprise the limit that is positioned at regulation.For example, from about 100 to about 200 scope also comprises from 110 to 150,170 to 190,153 to 162, and 145.3 to 149.6 scope.In addition, the limit until about 7 also comprises until about 5, until 3, and until about 4.5 the limit, and the scope in this limit, and for example from about 1 to about 5, and from about 3.2 to about 6.5.

Disclose generally and be used for from a plurality of targets the method and system of thin film layer cosputtering to the substrate.Can allow in sputtering chamber (particularly in sputter plasma) to the more accurate control of element kind from a plurality of (that is, 2 or more) target cosputtering.Thereby, the stoichiometry of sedimentary thin film layer can be controlled more accurately.For example, when forming transparent conductive oxide (TCO) layer and/or resistive transparent caching thing (RTB) layer in the production at photovoltaic devices, can control stoichiometric chemical constitution more accurately, especially during the high-speed sputtering technology in extensive manufacturing environment.

Can realize cosputtering from two or more targets that form by stupalith, metallic substance and/or alloy material.Target is cut into branch really can be selected according to the desired constituents of the thin film layer that will form.In most of embodiment, each target can have different compositions.Thereby each target can be to sputter plasma, also finally to the different element kind of sedimentary thin film layer supply.In addition, in order to assist in ensuring that this target, each target can have roughly the same size and dimension with other target.

In addition, the number of target also can be selected according to the desired constituents of the thin film layer that will form.In one embodiment, can use two targets to realize cosputtering.In other embodiments, can use three or more targets.No matter the number of the target that uses how, each target all can be positioned to towards substrate, to guarantee roughly to apply material from each target equably to substrate in certain embodiments.In certain embodiments, each target can be positioned to the center towards substrate.With respect to the normal direction axis perpendicular to the face of substrate, the adjustable angle of each target is made into control from the mixing of each target to the element kind of substrate supply.The interval that also can adjust between each target is supplied to the mixing of the element kind of substrate with control from each target.

Fig. 8 has shown a representative configuration on being used for from two target 201,202 cosputterings to the substrate of overlooking in the sputtering chamber 10.Two targets 201 shown in Fig. 8,202 are positioned to towards the center of substrate 10, make each target the center roughly tangent (being quadrature) in the lip-deep central point 205 of substrate 12, as respectively from target 201, axis in opposite directions 211 that 202 central vertical is extended and 212 junction are shown, intersect on the surface of substrate 12.

The axis in opposite directions 211,212 and y axis 204 angulation θ that extends from the central vertical of target 201,202 respectively ₁, θ ₂, y axis 204 is perpendicular to the surface of the substrate 12 that limits x axis 203.Angle θ ₁, θ ₂Can adjust the element kind of supplying from target 201,202 respectively with during the control sputter.

In a certain embodiments, angle θ ₁Can be substantially equal to angle θ ₂, to guarantee from each target 201,202 to plasma field 174 roughly element kind contribution uniformly.For example, angle θ ₁, θ ₂Each can be about 30 ° to about 60 °, such as about 40 ° to about 50 °.In a certain embodiments, angle θ ₁, θ ₂The two can be about 45 °.

In an alternative, angle θ ₁, θ ₂Can be different, make a target supply the element kind of out-of-proportion quantity to the surface of substrate 12.Adjust the angle θ of each target ₁, θ ₂Can help to control speed from the particular target sputter, thus stoichiometry when helping the deposition of this layer of control.In addition, the power with second target, 202 different amounts can be supplied to first target 201, so that independent control is from the sputtering rate of each target.

In a certain embodiments, can utilize a plurality of targets that the tco layer that comprises the composition (for example, cadmium stannate) of cadmium and tin is deposited on the substrate.For example, comprise that the tco layer of cadmium stannate can be from two ceramic targets depositions: (1) cadmium oxide compound target, and (2) tin-oxide target.The comparable single cadmium stannate target considerably cheaper of these targets, this can help to reduce the manufacturing cost of tco layer.Alternatively, comprise that the tco layer of cadmium stannate can be from two metal targets (for example, cadmium target and tin target) of sputter during comprising the sputtering atmosphere of oxygen deposition.

In a certain embodiments, substrate 12 can be carried through target 201,202 continuously with roughly consistent speed.

As mentioned, native system and method have special availability for the deposition of a plurality of thin film layers in the manufacturing of PV module especially CdTe module.Fig. 1 has presented the exemplary CdTe module 10 that can make according to system and method embodiment as herein described at least in part.This module 10 comprises the glass top plate as substrate 12, and it can be high transmission glass (for example, high transmission borosilicate glass), low iron float glass, or the glass material of other highly transparent.Glass is usually enough thick in providing support (for example, thick to about 10mm from about 0.5mm) to follow-up thin film layer, and flat is to be provided for forming the excellent surface of subsequent thin film layer.

Transparent conductive oxide in Fig. 1 (TCO) layer 14 is presented on the substrate 12 of module 10.Tco layer 14 allows light to pass through with the absorption of minimum, also allows simultaneously to shift to opaque metallic conductor (not shown) by the electric current that module 10 produces to one side.Tco layer 14 can have the thickness between about 0.1 μ m and about 1 μ m, for example from about 0.1 μ m to about 0.5 μ m, such as from about 0.25 μ m to about 0.35 μ m.

Resistive transparent caching thing (RTB) layer 16 is presented on the tco layer 14.This layer 16 has more resistive than tco layer 14 usually, and can help to avoid chemical interaction between tco layer 14 and the succeeding layer at protection module 10 during the processing of module 10.In certain embodiments, RTB layer 16 can have about 0.075 μ m between the 1 μ m, for example the thickness from about 0.1 μ m to about 0.5 μ m.In certain embodiments, RTB layer 16 can have about 0.08 μ m between the 0.2 μ m, for example the thickness from about 0.1 μ m to about 0.15 μ m.In certain embodiments, RTB layer 16 for example can comprise zinc oxide (ZnO) and stannic oxide (SnO ₂) composition, and be known as zinc tin oxide (" ZTO ") layer 16.

ZTO layer 16 can form by sputter, chemical vapour deposition, spray pyrolysis or any other suitable deposition method.In certain embodiments, ZTO layer 16 forms by sputter on tco layer 14 (for example, DC sputter or RF sputter).For example, layer 16 can use the DC sputtering method, has oxidizing atmosphere (for example, O ₂Gas) under the situation, by the DC electric current being applied to source metal material (for example, element zinc, element tin or its mixture) and the source metal material is splashed on the tco layer 14 and forms.

CdS layer 18 is presented on the ZTO layer 16 of module 10 of Fig. 1.CdS layer 18 is n type layers, and it generally includes Cadmium Sulfide (CdS), but also can comprise other materials, such as zinc sulphide, and zinc-cadmium sulfide etc. and composition thereof, and doping agent and other impurity.It is about 25% that CdS layer 18 can comprise that atomic percent reaches, for example the oxygen of atomic percent from about 5% to about 20%.CdS layer 18 can have wide bandgap (for example, from about 2.25eV to about 2.5eV, such as about 2.4eV), so that allow most of quantity of radiant energy (for example, solar radiation) to pass through.Thereby cadmium sulfide layer 18 is considered to the transparent layer on the device 10.

CdS layer 18 can form by sputter, chemical vapour deposition, chemical bath deposition and any other suitable deposition method.In a particular embodiment, CdS layer 18 forms on RTB layer 16 by sputter (for example, radio frequency (RF) sputter), and can have the thickness less than about 0.1 μ m.Reduce the quantity of radiant energy that absorbs by CdS layer 18 less than this thickness that reduces of about 0.1 μ m, increased the amount of the quantity of radiant energy of the CdTe layer 20 below arriving effectively.

CdTe layer 20 is presented on the cadmium sulfide layer 18 in the example modules 10 of Fig. 1.Layer 20 is p type layers, and it generally includes cadmium telluride (CdTe), but also can comprise other material.P type layer as module 10, CdTe layer 20 be with CdS layer 18 (promptly, n type layer) interactional photovoltaic layer, thereby with by producing electric current because its high absorption coefficient absorbs the most of quantity of radiant energy that enters module 10 and produces electron-hole pair from the absorption of quantity of radiant energy.CdTe layer 20 can have be adjusted with the band gap that adapts to the absorbing radiation energy (for example, from about 1.4eV to about 1.5eV, about 1.45eV for example), thus behind the absorbing radiation energy, produce the electron-hole pair of maximum quantity with maximum potential (volt).Electronics can pass the joint portion from p type side (that is, CdTe layer 20) and arrive n type side (that is, CdS layer 18), and on the contrary, the hole can go to p type side from n type side.Therefore, the p-n junction that is formed between CdS layer 18 and the CdTe layer 20 forms diode, and wherein charge unbalance causes producing the electric field of crossing over this p-n junction.Only allow the electron-hole pair that conventional electric current flows and separation is caused by light in one direction.

Cadmium-telluride layer 20 can form by any known technology, shifts deposition, chemical vapor deposition (CVD), spray pyrolysis, electrowinning, sputter, close-spaced sublimation (CSS) etc. such as steam.In certain embodiments, CdTe layer 20 can have about 0.1 μ m between about 10 μ m, for example the thickness from about 1 μ m to about 5 μ m.

Can use a series of backs to the exposed surface of CdTe layer 20 and form processing.These processing can be adjusted the functional of CdTe layer 20, and are got ready for follow-up being bonded on the contact layer 22 of back in its surface.For example, cadmium-telluride layer 20 can be at elevated temperatures (for example, from 350 ℃ approximately to about 500 ℃, such as from about 375 ℃ to about 424 ℃) annealing time enough (for example, from about 1 minute to about 10 minutes) to produce high-quality cadmium telluride p type layer.Under situation about being not wishing to be bound by theory, it is believed that usually slight p type is mixed in cadmium-telluride layer 20 (and module 10) annealing, perhaps in addition the adulterated CdTe layer 20 of n type convert stronger p type layer to relative low-resistance coefficient.In addition, but CdTe layer 20 recrystallize and experience grain growing during annealing.

In addition, copper can be added into CdTe layer 20.With suitable etching, copper is added into CdTe layer 20 can on CdTe layer 20, forms tellurium copper (Cu _xTe, 1≤x≤2 herein) the surface so that obtain low-resistance electric contact between cadmium-telluride layer 20 (that is p type layer) and the back contact layer 22.

Back contact layer 22 serves as the back electrical contact usually, and on the contrary, tco layer 14 serves as preceding electrical contact.Back contact layer 22 can be formed on the CdTe layer 20, and directly contacts with CdTe layer 20 in one embodiment.Back contact layer 22 is suitably formed by one or more highly conc materials, such as elemental nickel, chromium, copper, tin, aluminium, gold and silver, technetium, titanium or their alloy or mixture.In addition, back contact layer 22 can be single layer or can be a plurality of layers.In a certain embodiments, back contact layer 22 can comprise graphite, for example is deposited on one deck carbon on the p layer, and the back is with one or more layers metal, for example above-mentioned metal are arranged.If back contact layer 22 is made by one or more metals or comprised one or more metals, then it is by such as the technology of sputter or evaporation of metal and suitably coating.If it is made by graphite and copolymer mixture, or is made by carbon paste, then this mixture or cream are coated to semiconductor device by any suitable method that is used to scatter this mixture or cream, for example silk-screen, injection or by " scraping powder " cutter.After coated graphite mixture or carbon paste, this device can be heated this mixture or cream are changed into contact layer after the conductivity.If used carbon-coating, the thickness of this carbon-coating can be from about 0.1 μ m to about 10 μ m, for example from about 1 μ m to about 5 μ m.If back contact layer 22 is used the back contact layer of metals or as the part of back contact layer 22, the thickness of the back contact layer of this metal can be from about 0.1 μ m to about 1.5 μ m.

In the embodiment in figure 1, on the contact layer 22 of back, shown encapsulated layer 24.

In example modules 10, can comprise the miscellaneous part (not shown), for example bus-bar, outside wiring, laser-induced thermal etching etc.Module 10 can be divided into a plurality of independent unit, and they for example are connected in series so that obtain the voltage of expectation by the electrical wiring connection.Unitary each end that this series connects can be attached on the suitable conductor (for example lead or bus-bar), guides the device that is used to be connected to the electric power that use produced or the rotine positioning in other system into the electric current that photovoltaic is produced.Being used to obtain the unitary conventional means that this series connects is that module 10 is carried out laser grooving and scribing, thereby this device is divided into a series of unit that connect by interconnection.Equally, electrical lead can be connected on the positive and negative terminal of PV module 10 to provide lead to utilize the electric current that produces by PV module 10.

Fig. 2 has presented the example system 100 according to many aspects of the present invention, is used for going up a plurality of thin film layers of deposition in the PV module substrate 12 (Fig. 4) of carrying by this system 100.At first, should attention system 100 be not limited to the film or the thin film deposition processes of any particular type, described in more detail as this paper.

Illustrated system 100 comprises first process side 102, wherein is loaded into substrate on the carriage 122 along being transferred by the first direction shown in the arrow 103.First process side 102 comprises a plurality of different processing stands 104, these processing stands 104 be configured for when substrate when first process side 102 is transferred on substrate deposition the first film layer.Processing stand 104 can comprise the modular unit of continuous layout, and these modular units are aligned with execution and are used for the required whole procedure of processing of deposition the first film layer on substrate.106 places are introduced into first process side 102 in the entrance to have the carriage 122 that is loaded on the one or more substrates on it.Carriage 122 can manually be loaded in the load(ing) point 152, perhaps in an alternative, can use automaticmachines that carriage 122 is introduced load(ing) point 152.For example, robot or other automaticmachines can be used for this process.

Carriage 122 is removed from first process side 102 at relative exit point 108 places, and this exit point 108 can comprise external buffer thing 144.Again, carriage 122 can manually unload, and is perhaps received by the automatization mobile equipment that comprises robot machinery etc.

System 100 comprises second process side 110, this second process side 110 operationally is provided with respect to first process side 102, so as by second process side 110 along carry the carriage 122 leave first process side 102 (and substrate of carrying) thus by the second direction shown in the direction arrow 111.Second process side 110 comprise be configured to and arrange continuously with on the first film layer deposition second thin film layer a plurality of processing stands 112.The same with first process side 102, be disposed for when by second process side, 110 transport carriers 122 and substrate, carrying out along the processing module 112 of second process side 110 and be used for the required whole procedure of processings of deposit thin film layers.

First transition point 118 operationally is arranged between first process side 102 and second process side 110, receiving the substrate from the outlet 108 of first process side 102, and automatically substrate is moved to the inlet 114 of second process side 110.Transition point 118 can comprise the automaticmachines of any way of the transfer that is used to realize carriage 122.For example, transition point 118 can comprise automatization rotating disk 121, and the carriage 122 that it is configured to receive from the outlet 108 of first process side 102 is rotated counterclockwise 180 °, and introduces carriage 122 at inlet 144 places of second process side 110.For this purpose, this rotating disk 121 can comprise robotize or other automaticmachines of any way.In an alternative, transition point 118 can comprise finishing from the inlet 144 of outlet 108 to second process side 110 of first process side 102 and receives and the handling machinery of any way of the task of transport carrier 122.Should be understood that transfer and the delivery configuration that to utilize any way for this purpose easily.

In illustrated embodiment, first process side 102 and second process side 110 are parallel to each other substantially, make that the throughput direction 103 of each process side is parallel substantially with 111 and direction is opposite.This arranges that the spatial position from save production facility is useful.Yet, should be understood that easily that second throughput direction can be with respect to the axis of first process side 102 with any relative work angle setting (comprising in line or zero degree), and the invention is not restricted to illustrated structure among the figure.

By illustrated integral construction among Fig. 2, should be understood that easily that carriage 122 (having substrate) is moved through first and second process side 102,110 continuously, is used for depositing a plurality of thin film layers thereon.The structure of Fig. 2 is the open ended atoll texture, and wherein carriage 122 is positioned at the outside of system, and 106 places are introduced into first process side 102 in the entrance.Carriage is removed from this system 100 at exit point 116 places of second process side 110 subsequently.As mentioned above, this loads and uninstall process can manually or by automaticmachines be finished.

Still with reference to figure 2, can limit various processing stands 104,112 by vertical processing module 125, and the module 125 of each aligned adjacent is used for specific machining functions, as following described in more detail.Each module 125 can comprise the handling machinery 126 of independent drive and control.Substrate holder 122 is shelved on the handling machinery 126, and thereby moves through each module 125 in a controlled manner.In certain embodiments, handling machinery 126 can be roll-type handling machinery, band conveyor etc.For each corresponding module 125, handling machinery 126 can be equipped with independent driver (not shown among the figure).In an alternative, driving mechanism can be configured to be used for a plurality of handling machinerys 126 by the actuator drives disparate modules 125 of any way.Single handling machinery 126 can be associated with a plurality of modules 125.

Various modules 125 are by vertically directed, because carriage 122 passes through process side 102,110 transport substrates along vertical orientation.With reference to figure 4, exemplary carriage 122 is illustrated as the frame-type structure of being made by framing member 124.Framing member 124 is defined for the receiving positions of substrate 12, makes substrate 12 levels or admittance (with respect to their longitudinal axis) vertically in carriage 122.It should be understood that carriage 122 can be by the skeleton construction or the component limit of any way, so that carry one or more substrates 12 by process side along vertical orientation.In the embodiment of Fig. 4, carriage 122 is configured to be received in two substrates 12 on the level attitude.Should understandablely be that a plurality of substrates 12 also can be set, make the longitudinal axis of each substrate on the vertical position.Any orientation of the substrate 12 in the carriage 122 is all expected and is in the scope and spirit of the present invention.Framing member 124 can limit the open-type framework, and wherein substrate 12 is received in " the window opening " that is limited by carriage 122 basically.In an alternative, carriage 122 can limit backboard, and substrate 12 is provided with against this backboard.

The embodiment of illustrated carriage 122 is configured for admitting four substrates 112 among Fig. 5, wherein substrate 12 to being back-to-back relation.For example, a pair of substrate 12 is arranged in the upper frame part of carriage 112, and second pair of substrate 12 is arranged in the underframe part of carriage 112.The structure of Fig. 5 can be used for being added man-hour simultaneously when four or more substrates 12 in system 100, as following described in more detail with respect to illustrated deposition apparatus among Fig. 7.

Refer again to Fig. 2, one or more vertical deposition modules 128 that first process side 108 can supporting especially qualification vacuum sputtering chamber are used for the RTB layer of deposition zinc tin-oxide (ZTO) on by the substrate of wherein carrying.Equally, second process side 110 can comprise the one or more vertical sputter module 128 that limits the vacuum sputtering chamber, and the special configuration in vacuum sputtering chamber is used for depositing Cadmium Sulfide (CdS) floor on the RTB floor.In a particular embodiment, zinc tin oxide (ZTO) layer can be from a plurality of target depositions, as shown in Figure 8.For example, zinc tin oxide (ZTO) layer can exist under the situation of oxygen from zinc target and tin target deposition.

First process side 108 also can supporting especially one or more vertical deposition modules 128, and these vertical deposition modules 128 are defined in the tco layer of deposition cadmium stannate on the substrate, the vacuum sputtering chamber of subsequent deposition RTB floor in second process side 110 subsequently.For example, as mentioned above, tco layer can comprise cadmium oxide compound and tin-oxide from a plurality of ceramic target depositions.

The operation of vacuum sputtering chamber is well-known to those skilled in the art, and need not describe in detail at this paper.Basically, sputtering sedimentation is usually directed to from target (its for material source) blasting materials, and the material that the sprays form with thin film layer is deposited on the substrate.D.c. sputtering is usually directed near the metal target (being negative electrode) that voltage is applied to being positioned at the bottom of the chamber liner is gone up to form direct-current discharge.Sputtering chamber can have the atmosphere reactive (for example oxygen atmosphere) that forms the plasma field between metal target and the substrate.For magnetron sputtering, the pressure of atmosphere reactive can be approximately between 1mtorr and the about 20mtorr.Apply behind the voltage when atoms metal when target discharges, atoms metal and plasma reaction also deposit on the surface of substrate.For example, when atmosphere comprised oxygen, atoms metal was released in substrate from the metal target and forms metal oxide layer.Radio-frequency sputtering relates to by apply interchange (AC) or radio frequency (RF) between target source metal and substrate thereby signal excites the process of capacitive discharge.Sputtering chamber can have inert atmosphere (for example, argon atmospher), and this inert atmosphere has at approximately 1mtorr and the approximately pressure between the 20mtorr.

Fig. 6 has shown the overall schematic cross-sectional view of the exemplary vertical deposition module 128 that is configured to radio frequency or d.c. sputtering chamber 166.Power source 168 is configured to control and be fed to the direct current or the radio frequency power of chamber 166.Under the situation of direct current chamber 166, power source 168 applies voltage to produce voltage potential between negative electrode 170 and anode 172 to negative electrode 170.In illustrated embodiment, anode 172 is limited by locular wall.Glass substrate 12 is kept so that roughly relative with negative electrode 170 (it also is a target source material 176) by carriage 122.In case sputtering atmosphere is lighted and is promptly produced plasma field 174 and in response to negative electrode 170 with serve as the voltage potential between the locular wall of anode 172 and be held.Voltage potential causes the plasma ion in the plasma field 174 to quicken the surface that causes being sprayed to from the atom of negative electrode 170 substrate 12 to negative electrode 170.Thereby negative electrode 170 is " target " and the source material qualification that is used to form the particular type film of expecting on the surface of substrate 12.For example, negative electrode 170 can be the metal alloy target, for example the mixture of element tin, element zinc or different metal alloy.The target atomic reaction of oxygen in the chamber 166 and injection to be to form oxide skin on substrate 12, for example the ZTO layer.

Can in radio-frequency sputtering chamber 166 (Fig. 6), form Cadmium Sulfide (CdS) thin film layer by in inert atmosphere substantially, between ceramic target source material and substrate 12, applying interchange (AC) or radio frequency (RF) signal.

Although in Fig. 6 and Fig. 7, illustrate one power source, be understandable that usually and a plurality of power sources and corresponding target source can be linked together, in chamber 166, to produce the sputtering condition of expectation.

Fig. 6 illustrates the plus heater element 178 in the chamber 166.The plus heater element of configurable any way or structure in chamber 166 is with depositing temperature and the atmosphere in indoor maintenance expectation.

In the embodiment of Fig. 6, disposed vertical deposition module 128, be used for deposit thin film layers on the side of the substrate 12 that is oriented head for target source material 176.Fig. 7 illustrates an embodiment, wherein chamber 166 comprise be used for film be applied to the back-to-back substrate 12 that is fastened on carriage 122 outwards towards lip-deep pair of sputtering system, such as above with respect to illustrated in Fig. 5 and the structure of the carriage of describing 122.Therefore, utilize illustrated vertical deposition module 128 among Fig. 7, handle four substrates simultaneously, to deposit specific thin film layer thereon.

Although Fig. 6 and Fig. 7 have single target 176 owing to the side-view of being described shows, what should understand easily for those skilled in the art is as mentioned above and to use a plurality of targets shown in the exemplary embodiment of Fig. 8.

Refer again to the system 100 among Fig. 2, the independent handling machinery 126 that control is associated with the contiguous vertical deposition module 128 that is provided with, so that with controlled, constant linear speed transport carrier 122 and attached substrate by the vacuum sputtering chamber, thereby guarantee film is deposited on the surface of substrate equably.On the other hand, carriage 122 and substrate are introduced into and draw corresponding process side 102,110 in progressively mode.In this, the system 100 any structure of module, relevant handling machinery 126, vacuum locking valve 154 and CCU 156 that includes an inlet and an outlet.In addition, each process side 102,110 can comprise additional antivacuum module in its corresponding entrance and exit side, is used for carriage 112 is written into and carries system 100, with respect to transition point 118 buffering brackets 122, and before removing substrate, cool off substrate and carriage 122 from system 100.

For example, the vertical processing module 125 that comprises a plurality of adjacent settings with reference to figure 2, the first process side 102.In these modules 125 first limits load(ing) point 152, and carriage 122 is written into this system therein.As mentioned above, this can be manually or robotize finish.Corresponding handling machinery module in the load(ing) point 152 is shifted to vacuum load module 132 with carriage 122.This module 132 comprises inlet vacuum valve 154, the butterfly valve that it for example can be the gate type guiding valve or is activated by associated motor 156.Initial valve 154 be open and carriage 122 be transported to the module 132 from load-on module 152.Close inlet valve 154 then.At this moment, " slightly " vacuum pump 162 is pumped to initial " slightly " vacuum the millitorr scope from atmosphere.Black vacuum pump 162 for example can be the pawl formula mechanical pump that has Root's blower.After being pumped to the leap pressure of qualification, the valve 154 between the loading buffer module 134 of load-on module 132 and vicinity is unlocked, and carriage 122 is transferred in the loading buffer module 134.Valve 154 between the module 132 and 134 cuts out then, and load-on module 132 is drained, and initial valve 154 is opened so that next carriage 122 is received in the module." height " or " carefully " vacuum valve 164 is extracted the vacuum that raises out in loading buffer module 134, and module 134 can with the process gas backfill with the downstream processing chamber in the condition coupling.Thin vacuum pump 164 for example can be to be configured to be used for module is pumped to downwards and approximately is less than or equal to 9 * 10 ^-5The combination of the cryopump of holder.

Processing buffer module 136 is positioned at the downstream that loads buffer module 134, and under the specified vacuum pressure and condition in loading buffer module 134, the valve 154 between these two modules is unlocked, and carriage 122 is transported in the processing buffer module 136.Valve between the module 134 and 136 154 is closed then.Processing buffer module 136 is used for converting progressively carrying of carriage 122 to controlled linearity substantially and carries, make the leading edge of carriage 122 be in narrow, the limited interval of trailing edge of the previous carriage 122 of distance or distance (promptly, about 20mm) in, so that carriage 122 is transferred by downstream deposition module 128 with very little interval between each carriage 122 with controlled, constant linear speed.Thereby it should be understood that the valve 154 between the processing buffer module 136 and the first vertical deposition module 128 is opened in ordinary production operating period.Equally, the valve 154 between the adjacent vertical deposition module 128 is also opened.The valve 154 that is positioned at the exit of the second vertical deposition module 128 is also opened.By this way, the continuous flow of the carriage 122 of the vertical deposition module 128 by adjacent setting is maintained at the constant process velocity.

Still with reference to figure 2, post-treatment buffer module 138 is arranged on the downstream of last vertical deposition module 128, and the valve between these modules 154 is opened during normal process.When carriage 122 left vertical deposition module 128 with controlled constant linear speed, they entered this aftertreatment buffer module 138 and then to handle towards the outlet buffer module 140 bigger speed in tight downstream.Before this supplying step, the valve 154 between the

module

138 and 140 is closed and module 140 is taken out low by thin vacuum pump 164 and used the process gas backfill, with match machined district condition.In case satisfy these conditions, the valve 154 between the chamber is opened, and carriage 122 is transferred in the outlet buffer module 140 with higher relatively speed.Under leap pressure predetermined between module 140 and the lower exit module 142 (it can obtain in module 142 by black vacuum pump 162), between these modules accordingly valve 154 be opened and carriage 122 is transported in the outlet module 142.Outlet module 142 then can be to the atmosphere emptying.At this moment, open at the valve 154 in the exit of module 142, and carriage 122 is transported in the external buffer 144.

Carriage 122 moves into rotating disk 121 from external buffer 144, or is configured in other transfer device at transition point 118 places.Carriage is rotated or otherwise moves at transition point 118 places the position of the external buffer 144 that is used to enter the inlet point place that is positioned at second process side 110.

Processing buffer module 136 and post-treatment buffer module 138 can comprise one or more corresponding vacuum pumps 165, for example turbomolecular pump, and it directly is installed on the back of module, is used to keep the processing vacuum pressure.Similarly, vertical deposition module 128 also can comprise any type of vacuum pump, and for example turbomolecular pump 165, and it directly is installed on the back of module, each negative electrode relevant with corresponding module between.

Refer again to the system 100 of Fig. 2, the carriage 122 of transferring to the external buffer 144 relevant with second process side 110 is subsequently to be transferred by various vertical processing modules 125 with the above roughly the same mode of being discussed about first process side 102.Various valves 154, pump 162,164,165 and the operation of corresponding handling machinery 126 and order above only in progressively mode carriage 122 being moved into the purpose of processing modules and being described, carriage 122 is carried by vertical deposition module 128 with the constant linear speed in processing module subsequently.Vertical deposition module 128 in second process side 110 is disposed for deposition second thin film layer on the first film layer, for example aforesaid CdS layer.

Behind the outlet module 142 that leaves second process side 110, carriage 122 moves into one or more cooling points 148, and carriage and attached substrate are allowed to be cooled to the treatment temp of expectation therein before removing from system 100.The removal process can be manually or automatically, for example utilizes robotize machinery.

As discussed above, the system 100 among Fig. 2 and 3 is limited by a plurality of interconnected module, and each module is used for specific function.The corresponding handling machinery 126 of supporting independent module and valve 154 and associated actuator 156 are also suitably controlled at various functions.For the control purpose, each independent module can have the CCU supporting with it 158, with the individual feature of control corresponding module.A plurality of controllers 158 can be communicated by letter with centring system controller 160 again.Centring system controller 160 can monitor and control the function of (via controller 158 independently) any one of them module, obtains whole expectation transfer rate and processing when moving through system 100 with box lunch by the substrate of carriage 122 carryings.

Should be understood that easily that although deposition module 128 is described as the sputtering sedimentation module in this article in certain embodiments, the present invention is not limited to this specific depositing operation.Vertical deposition module 128 can be configured to the Processing Room of any other adequate types, for example CVD (Chemical Vapor Deposition) chamber, thermal evaporation chamber, physical vapor deposition chamber etc.In specific embodiment as herein described, first process side is configurable to be used to deposit the ZTO layer, and vertical deposition module 128 is configured to reactivity (use oxygen) direct current vacuum sputtering chamber.Each module 128 can supporting four direct current water-cooled magnetrons.As mentioned above, each module 128 also can comprise be installed to each negative electrode between the chamber, rear portion on one or more vacuum pumps.The vertical deposition module 128 relevant with second process side 110 can be configured to radio frequency vacuum sputtering chamber, and each module 128 comprises three radio frequency water-cooled magnetrons, is used to deposit the CdS layer from CdS pottery target material.These modules 128 also can comprise be installed in negative electrode between one or more vacuum pumps.

Fig. 3 illustrates the alternative system 100 of the system that is similar to Fig. 2, but is included in second transition point 120 between the inlet of the outlet of second process side 110 and first process side 102.The system that this is specific thereby define the successive ring, wherein carriage 122 is carried continuously by this system in the processing ring.Carriage 122 shifts out the outlet module 142 of second processing stand 110 and passes through cooling point 148.Carriage 122 moves into second transition point 120 then, and it can be as above about being configured that first transition point 118 is discussed.Carriage is transferred to the unloading point 150 that aligns with first process side 102 from last cooling point 148 then.When carriage 122 moved through unloading point 150, substrate removed from carriage.Again, this process can be manual or finishes by automatic robotization machinery.Empty carriage moves into load(ing) point 152 then, therein new substrate is loaded in the carriage 122.Carriage 122 and associated substrate are handled by first and second process side 102,110 then, as discussed above with respect to Figure 2.System 100 among Fig. 3 is unique, because this process is carried out in the mode of continuous loop, wherein carriage 122 does not need to remove from this system.Utilize the structure of Fig. 3 can greatly increase the efficient and the throughput capacity of system.

By utilizing as vertical deposition module 128 depicted in figure 7, can further improve the throughput capacity of the system of being described in Fig. 2 and 3 100, wherein module 128 is with the combination of two independent chambers of relation configuration in opposite directions substantially, so that deposit thin film layers on the surface of the back-to-back substrate in being installed in carriage 122 is as painting in the carrier configuration of Fig. 5.

In the embodiment of Fig. 2 and 3 system 100, in corresponding process side 102,110, aspirate and keep the processing vacuum separately.As previously discussed, carriage is 125 removals along first process side 102 from the vacuum processing module, are transferred to second process side 110, and introduce the vacuum processing module 125 of second process side 110.Should be understood that easily that the present invention also comprises system 100, wherein between first process side 102 and second process side 110, keep overall vacuum.In this type systematic, carriage 122 will be cushioned and be transferred to another process side from a process side in vacuum chamber.

The present invention also comprises and is used for a plurality of thin film layers are deposited on the whole bag of tricks embodiment on photovoltaic (PV) module substrate.These methods can perhaps be put into practice by any other structure of suitable system component with various system embodiment practices described above.Thereby it should be understood that the method according to this invention embodiment is not limited to system described herein structure.

In certain embodiments, this method comprises carries the substrate on the carriage by first process side along first direction, and deposits the first film layer when substrate moves through this first process side on substrate.Carriage is received in the exit of first process side, and moves to the inlet of second process side.Carriage and attached substrate are transferred then by second process side, with deposition second thin film layer on the first film layer.Substrate is removed from carriage at the unloading point place that is positioned at second process side outlet downstream, and new substrate is placed on the carriage at the load(ing) point place of the upstream that is positioned at first process side inlet.

This method can comprise in progressively mode carriage and attached substrate are moved into vacuum chamber and shift out vacuum chamber along first and second process side, for example, during deposition process, carriage and attached substrate transfer are passed through vacuum chamber again with the successive linear speed by a series of vacuum locks.

In a certain embodiments, first and second process side are normally parallel, and carriage moves through this first and second process side with the successive ring, and load(ing) point and unloading point are adjacent in this successive ring.

In another embodiment, first and second process side are normally parallel, and carriage loads in the ingress of first process side, and remove in the exit of second process side.

In another method embodiment again, thin film layer deposits in the vacuum chamber that limits along first and second processing stands, and carriage and attached substrate be moved through this system, and need not to interrupt the vacuum between first and second process side.

This printed instructions usage example comes open the present invention, comprises optimal mode, and makes those skilled in the art can put into practice the present invention, comprises manufacturing and uses any device or system, and carry out any bonded method.But the scope of the present invention's granted patent is defined by the claims, and can comprise other example that those skilled in the art expect.If this type of other example has the structural member of the literal language that is tantamount to claims, if perhaps they comprise that the literal language with claims there is no the equivalent construction element of essential distinction, then this type of other example is intended to be in the scope of claims.

Claims

1. system that is used for deposit thin film layers on photovoltaic (PV) module (10) substrate, described system comprises:

Be configured to admit the sputtering chamber (166) of described substrate (12);

At least two targets (201,202), it is positioned in described sputtering chamber (166) towards described substrate (12), make described target (201,202) sputter simultaneously is with to plasma field (174) source of supply material, be used on the surface of described substrate (12), forming film, wherein said a plurality of target (201,202) be located such that from each target (201,202) axis in opposite directions (211,212) that central vertical is extended is located to assemble at the described lip-deep point (205) of described substrate (12); And

Be connected to the independently power source on each target.

2. the system as claimed in claim 1 is characterized in that, comprises two targets (201,202) in described sputtering chamber.

3. system as claimed in claim 1 or 2, it is characterized in that, from each target (201,202) the described axis (211 in opposite directions that central vertical is extended, 212) with y axis (204) angulation perpendicular to the described surface of described substrate (12), wherein the angle ranging from about 30 ° to about 60 °, be preferably about 45 ° by what each target (201,202) formed.

4. system as claimed in claim 3 is characterized in that, the described angle that is formed by each target (201,202) is roughly the same.

5. system as claimed in claim 3 is characterized in that, the described angle that is formed by each target (201,202) is different.

6. as the described system of any aforementioned claim, it is characterized in that, the power of different quantities is supplied to each target (201,202), so that independent control is from the sputtering rate of each target (201,202).

7. as the described system of any aforementioned claim, it is characterized in that, described system configuration becomes to make described substrate (12) to be carried the described point (205) that convergence limited that passes through by the described axis (211,212) in opposite directions of each target (201,202) continuously.

8. one kind is used for going up the method that deposits a plurality of thin film layers in photovoltaic (PV) module substrate (12), and described method comprises:

Described substrate (12) on the carriage is carried by sputtering chamber (166); And

At least two targets of sputter (201 when described substrate (12) moves through described sputtering chamber (166), 202), on described substrate, to form film, at least two targets (201 wherein, 202) in described sputtering chamber (166), be positioned to towards described substrate (12), make described target (201,202) sputter simultaneously is to provide source material to plasma field (174), be used on the surface of described substrate (12), forming thin film layer, and wherein said at least two targets (201,202) be located such that the axis in opposite directions (211,212) that extends from the central vertical of each target (201,202) assembles at the described lip-deep some place of described substrate (12).

9. method as claimed in claim 8 is characterized in that, each target comprises the source material of the source material that is different from other target (201,202).

10. method as claimed in claim 8 or 9 is characterized in that, two targets in location in described sputtering chamber (166).

11. method as claimed in claim 10 is characterized in that, described two targets (201,202) that are positioned in the described sputtering chamber are second target that comprises first target of cadmium oxide compound and comprise tin-oxide.

12. each described method as claim 8 to 11, it is characterized in that, from each target (201,202) the described axis (211 in opposite directions that central vertical is extended, 212) with y axis (204) angulation perpendicular to the described surface of described substrate (12), wherein the angle ranging from about 30 ° to about 60 °, be preferably about 45 ° by what each target (201,202) formed.

13. each the described method as claim 8 to 12 is characterized in that the described angle that is formed by each target is roughly the same.

14. each the described method as claim 8 to 13 is characterized in that, the described point that each substrate is limited by the convergence by the described axis in opposite directions of each target by continuous bearing with the linear speed of constant.

15. a method of making the Cadimium telluride thin film photovoltaic devices, described method comprises:

From first target and second target including transparent conducting oxide layer is splashed on the substrate simultaneously to each described method of 14 according to Claim 8, wherein said first target comprises cadmium, and second target comprises tin, and wherein said first target and second target are located such that the axis in opposite directions that extends from the central vertical of each target assembles at the lip-deep point of described substrate, described axis in opposite directions and y axis perpendicular to the described surface of described substrate form about 30 ° to about 60 ° angle;

Deposition resistive transparent caching thing layer on described including transparent conducting oxide layer;

On described resistive transparent caching thing layer, deposit cadmium sulfide layer; And

On described cadmium sulfide layer, deposit cadmium-telluride layer.